Lithium metal is being intensively pursued as an anode due to its high specific capacity. However, dendrite formation, Li loss and short circuiting upon cell cycling presently impede its use. Furthermore, the flammability of liquid electrolytes poses a severe safety hazard. Replacement of organic liquids by solid electrolytes could pave the way for using lithium metal, simultaneously improving specific energy and battery safety.

Efforts continue on ceramic electrolytes. Challenges include the formation and manufacture at scale of sufficiently thin, highly dense, pinhole-free sheets of ceramic electrolytes, required for high power devices. Such electrolytes must also maintain contact with the solid electrodes while inhibiting Li dendrites and be durable towards volume changes of the electrodes as well as to external shock.

Polymer electrolytes have been developed for a number of years. They can exhibit good adhesion and contact to the electrodes, but typically have lower conductivity and limited capability of suppressing dendrite formation.[i]

To date, ceramic and polymer electrolytes remain a challenge. Composites of particulate ceramics embedded within polymer electrolytes have been investigated to improve the conductivity and mechanical properties.^[ii] Our approach is to create ordered composite electrolytes, which allows modification of the mechanical properties of the composite while retaining good overall ionic conductivity.

The conductivity of the polymer-ceramic composite is 1.5E-4 S/cm at 25 °C. The results for different ceramic-polymer compositions indicate that the mechanical properties of the composite can be modified by the presented approach. Mechanical testing and the results of galvanostatic cycling will be reported.